Mighty man o’ war
© Getty
The Portuguese man o’ war (Physalia physalis) is one of the most unusual predators on Earth. At first glance they might be mistaken for jellyfish, but they’re actually made up of a colony of organisms called a siphonophore. Tentacle-bearing polyps hang down 50 metres into the water to catch prey, with each tentacle coated in barbed venom-carrying tubes to paralyse and kill creatures.